Improvement in steam-engine piston-packing



vsind (tj-lliure.

JOHN GATES, OF PORTLAND, OREGON.

Lette/rs Pate/nt No. 91,010, dated June 8, 1869.

IMIElRO'VEMENT IN STEAM-ENGINE IPISTON-1E.ACKING.` p

The Schedule referred to in these Letters Patent and making part of the same.

of metal, may be used, and the packing-rings may be adj usted without the employment of screws, thereby dispensing with the usual follower, and tightening and adjusting-screws, commonly employed.

Figure l represents a transverse section of a piston head and packing, arranged according to my improvements, taken on the linea: fr ofiig. 2; and

Figure 2 represents a horizontal section of the same.

Figures 3 o 9, represent sectional detail views of certain modications of my improvements.

Similar letters of reference indicate corresponding parts.

I propose to construct a piston, A, of one piece of metal, as represented in the drawings, having the central hub B, and three segmental webs C, uniting the two side walls.

I alsoform an inner segmental packing-ring, preferably in three segments, and divided into two'parts, 0r rings a b, the-wholey being comprised in six pieces.

Each of these segmental parts is provided with a web on its inner face, representing the arc d, supporting at' their centres the rollers e, which are provided with the pins j', projecting inward, and taking ntoholes in the spring g, which is employed to press the packing-ring against the cylinder.

The surfaces of the rollers care intended to project inward slightly beyond the line of the inner curvature of the segments C, so as to taket-he pressure of the spring, but not so far as to cause the packing-ring to be forced out beyond the counterbore of the cylinder, which greatly facilitates the entrance ot the. piston into the cylinder.

Washers may be placed on the pins f, to increase the pressure ofthe spring g'. The said spring is only required to be about two-thirds, or slightly more, of a circle, in order to bear equally upon all the segments. It is, by thisarrangement, easily placed in its position around the hub B, and between the side walls of a piston, made of one piece. The rollers e are designed to equalize the pressure on each halfof the packing-ring, but, if preferred, they may be dispensed with, and the springbe .made to bear directly on the inner faces ofthe arcs d.

-Thc exterior face of the packing-ring is grooved at each side, for the insertionof the outer segmental rings h.

I also propose to introduce the springs 'i between the 'two parts, a and l), of the packing-ring, for pressing them against the side walls of the piston, by whichthe surfaces may be ground together, to produce a more perfect joint, and also to regulate the admission of steam under the packing-ring. If the working-pressure be one hundred pounds, the springs 'i may be gauged to a resistance slightly less, say ninety-nine; then when steam enters, it will press the two parts ot the ring together', and tind its way under 4.the ring,

.where it will be retained at the latter end of the stroke,

when the pressure isrednced by cutting ofil the springs i, throwing the parts a and lmtgainst the walls of the piston, and closing the passage as soon as the pressure falls below thc powerof the said springs.

Under some circumstances it may be preferred to make the segments of the packing-ring whole, instead ot' dividing them into the two parts a and b, under which arrangement it will serve a good purpose; but I prefer to divide it as shown.

In some cases I design to divide the packing-ring into outerl and inner rings, a; y, as represented in the modifications, figs. 3 to 9, and arrange the spiral or other springs to bear equally upon the said parts, to

force them against the walls of the piston, whereby two steam-tight joints are made against each wall, each part, a: y, being acted upon separately.

I also propose in some cases to separate the webs d from the inner rings, and arrange them to bear upon the rings in two points z z, as represented in iig. 8, thus applying the action ofthe springs at six equidistant points.

Havingthus described my invention,

I claim `as new, and` desire to secure by Letters Patentl 1. The combination, with the piston-head A, made in 'one piece, of the segmental packing-ring, having the interior arcs d, and the spring y, substantially as specilied.

- 2. The combination, with the spring g, and segmental packing-ring, divided into two parts, a and b, of the equalizing-rollers e, substantially as specied.

3. The combination with the segmental packingring, divide-d in two parts, a and b, of the springs i, sub- `stantially as specified.

4. The piston-head A, provided with the segmental webs ,0, and combined with the spring g, and segmental packing-ring, substantially as specilied. f j

Y JOHN GATES.

Witnesses:

L. M. PARRISH, GEO. ABERNETHY. 

